This invention relates to a novel polyhydroxyphenylene ether resin having an optional number of hydroxyl group(s) which is a reactive functional group in the molecule and a process for preparing the same.
More specifically, this invention relates to a process for preparing a novel polyhydroxyphenylene ether resin which comprises subjecting a phenol-substituted compound having hydroxyl group as a substituent to oxidation polymerization or subjecting said compound with another phenol-substituted compound to oxidation copolymerization, and a novel polyhydroxyphenylene ether resin excellent in coating property, plating property, adhesion property and gas barrier property, and useful for lamination and further as a compatibilizing agent of a polymer alloy.
In recent years, demands for resin materials have been diversified and sophisticated so that development of a resin having a reactive functional group has been demanded strongly. This is because, for example, in a non-compatible polymer blend, in order to obtain a polymer blend showing microdispersion form and having firm interfacial strength, it is effective to use, as a compatibilizing agent, a block polymer or a graft polymer having a segment which has affinity to both polymers to be blended. One of the important methods of synthesizing these polymers is a method of bonding polymers each having a functional group reactive with each other.
As a method of functionalizing a polyphenylene ether (hereinafter called "PPE"), there has been known examples of introducing various functional groups using a terminal phenolic hydroxyl group as a reaction site. For example, there are a terminal carboxylic anhydride-modified PPE disclosed in Japanese Provisional Patent Publication No. 199754/1988 or Japanese Provisional PCT Patent Publication No. 500456/1987, a terminal alcoholic hydroxyl-modified PPE disclosed in U.S. Pat. No. 4,744,708 and a terminal glycidyl-modified PPE disclosed in U.S. Pat. No. 4,732,937. However, since in these examples, each number of a reaction site and a functional group is one at most per one molecule of a polymer, said examples cannot be said to be satisfactory in the point of optimum number of functional groups.
One of the effective methods of introducing a functional group is copolymerization with a monomer compound having a functional group. However, in known copolymers until now concerning PPE, a substituent of a main chain benzene ring is confined only to an alkyl group, an alkenyl group, an aromatic group, an oxyalkyl group and a halogen atom.